Changing a piece

Once a piece is on the stage, whatever you send Perlin next is a change to it. Perlin reads the code of the version showing, the values you've set on its controls and the conversation so far, then makes a new version. The one before is kept, so a change never costs you what you had.

Making a change

1. Check the version on the stage

   A change builds on the version that is showing. To carry on from an earlier one, go back to it first (see Going back and branching).

2. Describe the change

   The prompt box reads "Describe a change…", with ideas such as "Make it feel warmer" or "Add slow camera drift". Write what should be different, and anything that must stay as it is.

3. Send it

   While Perlin works, the stage reads Perlin · Revising, the new code streams in, and for a focused change the readout counts the edits as they land.

4. Play the new version

   Under Perlin's reply, a version chip shows the piece's title, its number and engine (such as "v3 · WebGL 3D") and Live while it is the one on the stage.

With Plan first on, a change gets a short plan before anything is built, often a point or two for a small change (Plan first).

How Perlin changes a piece

Perlin picks the lightest way to make the change:

• A focused change, such as a colour, a speed or one new control, is made as exact edits to the lines that need it. The rest of the code is left alone, it is quicker, and it usually costs fewer tokens than a new piece.
• A sweeping change, or a new idea, is a rewrite of the whole piece.
• A change to the motion alone (its timing, words or states) updates the motion without touching the code.

Whatever you didn't ask to change stays: the engine, the controls, the palette, the motion and the composition. Controls keep their names, so the values you've set in the parameters panel carry over to the new version. Perlin works from the code on the stage, including anything you changed by hand in the code editor.

Writing a good follow-up

• Ask for one or two things at a time. Several small messages land more reliably than one long list.
• Say where and how much: "twice as many stars, only in the top third".
• Name the control you want: "add a slider for fog density".
• Say what to keep: "keep the camera exactly where it is".

For sound to be added, Sound FX has to be on (Sound FX, Textures and 3D).

Asking a question

A message that asks rather than requests, such as "why does the trail flicker at the edges?" or "which control sets the density?", gets a short answer, and the piece stays as it is. A question is a request like any other and is charged in tokens.

Changing the engine

To move a piece to another engine, choose 3D, Shader or 2D in the engine picker and send a message. Perlin recreates the idea in that engine as a new version. The values you set on the old controls don't carry across, since the new piece has controls of its own.

Bringing in images, files and assets

You can attach things to a change as you can to a first prompt. Reference images bring their look into the piece, files bring what they hold (a palette from a brand guide, copy from a brief) and your assets go into the piece as they are. Send them without any words and Perlin brings them into the current piece: the images' look, the files' contents, the assets themselves. See Reference images and files and Using assets in a piece.

Going back and branching

Every change is a new version, and every version is kept:

• Click an earlier version chip in the conversation to bring it back to the stage. A chip says Restore when you point at it and Live on the one showing.
• Press [ and ] to step back and forward through the versions.
• Open Versions on the rail, or press H, to see them all.

The next change builds on whichever version is showing, so going back and asking for something else branches the piece from that point. Versions and history has the details.

Starting again

For a different idea, press New piece in the top bar. It opens an empty stage with a fresh conversation, and the piece you were on stays in My pieces (L). Perlin reads the whole conversation with each request, so an unrelated idea starts cleaner in a piece of its own.

To start over on the same piece, say so: "start again: a slow underwater scene instead". Perlin rewrites it as a new version, and the earlier ones are still there.

Stopping a change

While Perlin works, the send button becomes a square Stop button. Pressing it ends the request and nothing new is added; the version on the stage stays. A stopped request is charged for the work it did before you stopped it. More in Long builds and Keep going.

Related

• Versions and history
• Asking Perlin for a piece
• Tuning with parameters
• Editing the code